This invention relates generally to container filling systems and more particularly to container filling systems which determine a container fill level based on direct sensing of products being filled.
Flowable products, particularly products in liquid form are stored, transported, and sold in containers such as bottles and cans. In a small to mass-production environment large numbers of such containers are filled with a known amount of liquid product by filling machines dedicated to that purpose.
Known container filling machinery typically meters the amount of product for a specific container by either weight or volume prior to the container actually being filled. Prior art machinery thus does not use the dynamics of the material being filled to aid in or to be an active participant in the filling process of a container. Furthermore, prior art machinery that meters by weight does not guarantee that a container is filled to proper or desired volume fill level (it could be fooled by foreign objects).
This metering is performed by devices such as gear pumps, diaphragm pumps, piston pumps, peristaltic pumps, flow meters, worm gear, lobe gear pumps, etc. This is an extremely expensive procedure due in part to the cost involved in the pumps, which need to be extremely accurate and reproducible. These pieces of equipment as well as the related flow meters require a further array of very expensive control electronics and equipment.
These systems are also very difficult to clean because of all the intricate pump parts and piping that is required to allow the system to function properly. Another drawback is the sensitivity of these filling machines to viscosity of the product and the temperature of the product and pressure used to fill the product as well as the composition of the product.
Another drawback to these devices is their inability to pump and meter accurately and continuously materials that contain particulate matter within the formula such as pumice in a hand soap. This type of material usually destroys the pump's ability to meter, and causes wear on gear pumps, piston pumps, peristaltic pumps, worm gear pumps, lobe gear pumps, etc.
Accordingly, there is a need for a container filing apparatus which is simple in operation and tolerant to various materials.